The present invention relates generally to systems, and particularly to power testing a system chassis.
The present invention is an improvement of the existing method of power testing a system chassis. It is desirable to measure the power characteristics of a system chassis under the conditions of actual use. For example, it is useful to correlate the amount of power consumed by the chassis during operation with the temperature inside the chassis. Also, it is desirable to test the maximum power under which the chassis can operate. Thus, what is needed is an apparatus and method for testing a computer chassis under operating conditions.
A computer system is generally contained in a chassis. A chassis is typically made up of a housing and a backplane. A power supply may be located either outside the chassis or within the chassis. Within the chassis, computer devices or computer circuit boards are plugged into the backplane. A controller or host controls these computer devices through the backplane. In addition, a fan may be housed within the chassis to cool the system.
In order to accurately test the power characteristics of a system chassis, it is necessary to simulate operating conditions. One method of measuring the power characteristics of a chassis consists of attaching a load generator to the system""s power supply. However, because the load generator is not plugged into the backplane inside the chassis, it is not a true test of the system under operating conditions. Moreover, because the load generator is not inside the chassis, it is impossible to provide a thermal or cooling analysis of the chassis. Another method of testing the chassis is to plug resistor load boards into the backplane of the chassis. However, in order to change the operating conditions of the system it is necessary to physically change the load boards. Thus, using this method, it is impossible to test the power characteristics under dynamic operating conditions.
In summary, the present invention is a load test board for plugging into a backplane of a chassis. The load test board has a CPU, a variable load controlled by the CPU, a voltage sensor to detect voltage across the variable load, and a current sensor to detect current through the variable load.
Another aspect of the present invention is a chassis having a backplane and a load test board plugged into the backplane. The load test board has a CPU, a variable load controlled by the CPU, a voltage sensor to detect voltage across the variable load, and a current sensor to detect current through the variable load.
Yet another aspect of the present invention is a method of testing a chassis including inserting a test board into a backplane of the chassis, providing a variable load on the test board, using circuitry on the test board to control the variable load, and measuring current through the variable load and voltage across the variable load.